This paper analyzes the micro-strip patch antenna performance by the theoretical method, such as fringing effect, effective length, resonant frequency, quality factor, bandwidth, efficiency. Based on the study of micro-strip antenna, analyzes the dielectric ceramic patch antenna for GPS module. Most of ceramic patch antennas have directional radiation patterns. For omni- directional GPS antenna, we change the antenna on the GPS board from dielectric ceramic patch antenna to PIFA antenna. The measured radiation patterns of PIFA antenna that is newly applied to GPS board are smilar to conventional omni-directional antenna.